A polymer and a method for preparing the same are provided. The polymer includes a first repeat unit and a second repeat unit. In particular, the first repeat unit is

##STR00001##

and, the second repeat unit is

##STR00002##

wherein R.sup.+ is

##STR00003##

A.sup. is F.sup., Cl.sup., Br.sup., I.sup., OH.sup., HCO.sub.3.sup., HSO.sub.4.sup., SbF.sub.6.sup., H.sub.2PO.sub.4.sup., H.sub.2PO.sub.3.sup., or H.sub.2PO.sub.2.sup.; X is

##STR00004##

i and j are independently 0, or an integer from 1 to 4; Y is O, S, CH.sub.2, or NH; R.sup.1 is independently C.sub.1-8 alkyl group; and, R.sup.2 and R.sup.3 are hydrogen, or independently C.sub.1-8 alkyl group.

An ion exchange membrane is provided. The ion exchange membrane includes a reaction product of a polymer and a cross-linking reagent. The polymer includes a first repeat unit, and a second repeat unit. In particular, the first repeat unit is

##STR00001##

and, the second repeat unit is

##STR00002##

wherein R.sup.+ is

##STR00003##

A.sup. is F.sup., Cl.sup., Br.sup., I.sup., OH.sup., HCO.sub.3.sup., HSO.sub.4.sup., SbF.sub.6.sup., BF.sub.4.sup., H.sub.2PO.sub.4.sup., H.sub.2PO.sub.3.sup., or H.sub.2PO.sub.2.sup.; X is CH.sub.2.sub.iYCH.sub.2.sub.j, i and j are independently 0, or an integer from 1 to 4; Y is O, S, CH.sub.2, or NH; R.sup.1 is independently C.sub.1-8 alkyl group; and, R.sup.2 and R.sup.3 are hydrogen, or independently C.sub.1-8 alkyl group; and, the cross-linking reagent is a compound having at least two imide groups.

The invention relates to novel polymers containing grafted sodium or lithium bis(sulfonyl)imides, to the methods for the production thereof, and to the uses of same as electrolytes in batteries.

Provided are: a practically excellent polymer electrolyte composition having excellent chemical stability of being resistant to strong oxidizing atmosphere during operation of fuel cell, and achieving excellent proton conductivity under low-humidification conditions, excellent mechanical strength and physical durability; a polymer electrolyte membrane, a membrane electrode assembly, and a polymer electrolyte fuel cell each using the same. The polymer electrolyte composition of the present invention comprises at least an ionic group-containing polymer (A) and a phosphorus-containing additive (B), the phosphorus-containing additive (B) being at least one of a phosphine compound and a phosphinite compound. The polymer electrolyte membrane, the membrane electrode assembly, and the polymer electrolyte fuel cell of the present invention are structured by the polymer electrolyte composition.

The invention relates to novel polymers containing grafted sodium or lithium sulphonamides, production methods thereof and uses of same as electrolytes in batteries.

It is an object of the present invention to provide a polymer electrolyte material which has excellent proton conductivity even under the conditions of a low humidity or a low temperature and is excellent in mechanical strength and fuel barrier properties, and which moreover can achieve high output, high energy density and long-term durability in forming a polymer electrolyte fuel cell therefrom, and a polymer electrolyte form article using the same and a method for producing the same, a membrane electrode assembly and a polymer electrolyte fuel cell, each using the same. The present invention employs the following means. Namely, the polymer electrolyte material of the present invention is a polymer electrolyte material including a constituent unit (A1) containing an ionic group and a constituent unit (A2) substantially not containing an ionic group, wherein a phase separation structure is observed by a transmission electron microscope and a crystallization heat measured by differential scanning calorimetry is 0.1 J/g or more, or a phase separation structure is observed by a transmission electron microscope and the degree of crystallinity measured by wide angle X-ray diffraction is 0.5% or more. Also, the polymer electrolyte form article, the membrane electrode assembly and the polymer electrolyte fuel cell of the present invention are characterized by being composed of such polymer electrolyte materials.

Novel PBI films which may be used in electrochemical cells, such as redox flow batteries, are disclosed. Additionally, disclosed herein are membranes which comprise the novel PBI films which may be free from an organic solvent, and have a tensile strength at break of at least 25 MPa after drying.

A separator for an electrolytic cell alkaline electrolysis (1) characterized in that the separator has a residual non-aqueous solvent amount of less than 5 wt %, relative to the total dry weight of the separator.

Blend membranes based on polybenzimidazole (PBI) and polymeric ionic liquids (PILs), wherein said PBI and aliphatic PIL blend enhances H.sup.+ and OH.sup. ions conductivity, are provided. In particular, the blend membrane includes polybenzimidazole (PBI) and poly (diallyl dimethyl ammonium) trifluoromethane sulphonate with enhanced proton and hydroxyl ion conductivity.

An ultrafiltration membrane comprising: (i) a first polymer, and (ii) a second, charged polymer wherein the first polymer and second polymer have different hydrophobicities.